The project will complete an ongoing study of covert dyskinesia aimmd at determining the extent to which maintenance antipsychotic drug therapy conceals an underlying dyskinesia and the extent to which benztropine can uncover such a dyskinesia while the patient is still on antipsychotic drugs. Studies of potential drug approaches to tardive dyskinesia will also be carried out including studies of dopamine agonists and presumed gamma-amino-butyric acid agonists. Newer potential antipsychotic drugs without dopamine-blocking properties will be studied for their effects on both schizophrenia and tardive dyskinesia.